When you notice that there are changes in the current page version that you are not satisfied, you can rollback to an older version of that page quickly.
To restore an older version, click 
corresponding to your desired version in the Page History page.
Note
Restoring an older version will create a copy of that version. For example, if the [current version (v.2)] is restored to the [older version (v.1)], Wiki will create a new version (v.3) containing content of v.1. The version v.3 will become the current version.